It might be an understatement to say the Supreme Court on Wednesday seemed skeptical that corporations have "personal privacy" rights that would prevent the government from releasing documents about them.

The case stems from AT&T's claim that the government should not release certain information about the company when requested under federal public records laws.

AT&T convinced the U.S. Court of Appeals for the 3rd Circuit that an exception in the federal Freedom of Information Act for "personal privacy" extended to the corporation itself. It pointed out that in one provision of the federal law, Congress defined "person" to include "an individual, partnership, corporation, association or public or private organization."

But Chief Justice John G. Roberts Jr. told AT&T lawyer Geoffrey M. Klineberg that he did not buy his "central argument" that because "person" includes corporation in one part of the statute, "personal" must include corporations in another part.

"I tried to sit down and come up with other examples where the adjective was very different from the root noun," Roberts said. "It turns out it is not hard at all.

"I don't think there's much to the argument that because 'person' means one thing, 'personal' has to be the same relation," Roberts concluded.

Klineberg recovered to say his client was not relying solely on the "grammatical imperative."

He said the "definition should be applied, so long as it makes sense to do so in light of the text and structure of the statute as a whole."

Because the case comes nearly a year to the day after the Supreme Court loosened restrictions on corporate electoral spending in Citizens United v. Federal Election Commission, it was closely watched for whether the court was ready to extend other corporate privileges.

Instead, criticism of the notion came from all quarters.

Justice Antonin Scalia asked for any example "from anywhere, that anybody refers to the interests of a corporation as the 'personal privacy' of General Motors? I cannot imagine somebody using the phrase like that."

The case began when AT&T notified the Federal Communications Commission that it might have overcharged the government for certain work. An investigation led to a settlement. The FCC released certain documents it had gathered, but withheld others under exceptions in the law that cover trade secrets and individuals' right to privacy.

But when CompTel, a trade association representing some of AT&T's competitors filed a FOIA request for more of the documents, AT&T went to court to keep the FCC from making the disclosure.

Justice Ruth Bader Ginsburg noted that the law contains many exceptions, including for medical records, trade secrets and financial records. What else does the company need to protect, she asked Klineberg.

One example, he said, would be e-mails detailing frank discussions about government regulators, or candid descriptions of some of the company's clients. Even if the individual memo-writer's name was redacted, he said, competitors could use the information to cause harm to the company.

Justice Stephen G. Breyer pressed Klineberg on whether he could come up with an example of that happening in the 35 years since the law has been in place. When Klineberg said he couldn't, Breyer suggested that was because "these organizations that have interests in privacy are actually taken care of by the other 17 exemptions here."

Things were going so well for the government that Assistant Solicitor General Anthony A. Yang tried to temper the justices' enthusiasm for his case. When Scalia and Justice Sonia Sotomayor suggested the court should view the exceptions narrowly, Yang said not necessarily.

"The FOIA exceptions that are at issue here protect very important values that Congress deemed to warrant exceptions from the rule," Yang said.

The government's ambivalence can be explained by another case currently at the court, where it is withholding documents than an individual is seeking to get under the FOIA law.

"The government has broader interests beyond a single case," Yang said.